package com.lazy.rabbit.demo.topics;

import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.Channel;

public class EmitLogTopic {

    private static final String EXCHANGE_NAME = "topic_logs";

    public static void main(String[] argv){
        Connection connection = null;
        Channel channel = null;
        try{
            ConnectionFactory factory = new ConnectionFactory();
            factory.setHost("localhost");

            connection = factory.newConnection();
            channel = connection.createChannel();

            channel.exchangeDeclare(EXCHANGE_NAME, "topic");

            String routingKey = getRouting(argv);
            String message = getMessage(argv);

            channel.basicPublish(EXCHANGE_NAME, routingKey, null, message.getBytes("UTF-8"));
            System.out.println(" [x] Sent '" + routingKey + "':'" + message + "'");

        }catch(Exception e){
            e.printStackTrace();
        }finally{
            if(connection != null){
                try{
                    connection.close();
                }catch(Exception ignore){
                }
            }
        }
    }

    private static String getRouting(String[] strings){
        if(strings.length < 1)
            return "anonymous.info";
        return strings[0];
    }

    private static String getMessage(String[] strings){
        if(strings.length < 2)
            return "Hello World!";
        return joinStrings(strings, " ", 1);
    }

    private static String joinStrings(String[] strings, String delimiter, int startIndex){
        int length = strings.length;
        if(length == 0)
            return "";
        if(length < startIndex)
            return "";
        StringBuilder words = new StringBuilder(strings[startIndex]);
        for(int i = startIndex + 1; i < length; i++){
            words.append(delimiter).append(strings[i]);
        }
        return words.toString();
    }
}
